Spark plug wires

Let's discuss plug wires. Facts and myths. Tractor with points must have copper core wires? Electronic ignition must have carbon core? Truth? Why? What happens if you use wrong wires? I got 4-5 sets of carbon core wires in a box from an estate sale...... Just wondering if they will work on a Cub?

Grandpa:
Carbon core were invented to reduce static on the radio in your pick-up. They might work on the cub, but could have performance issues. The coil and points set up need the direct placement of the spark to the plug for better firing. of the poor fuel we use now days. I think you can prove that to yourself by using them on one of your cubs. I don't think it will take too long before you are buying solid core wires.

Carbon core wires will give you hard starting or no starting especially if you have a 6 volt system.
I only use solid core wires on any gas tractors as they would of been made before any high energy ignition systems were made.

That's what I normally have. But got several sets of carbon core, brand new. Cheap, but good ones. Napa brand. Wanted to try them

Have to wonder about all the gas engines in the 60s that had carbon core wires from the factory. How did they run? Must had been due to being 12 volts. But they did run and run well they did. carbon wires will increase the spark voltage as the coil(inductor) discharges at higher voltage, based on resistance. But the plug air gap sets most of the resistance.

I ran carbon core on my Farmall 350 for years - eventually I replaced them with copper core when I was trying to fix a points issue - part of a parts cannon repair. I still run a single carbon core wire on my 1450 Cub Cadet.

Some of the points to electronic ignition conversions specify the carbon core type wires.

Never had any issues with running carbon wires on point/coil style ignitions. The only place I have found that you shouldnt is on a magneto.

(quoted from post at 14:50:34 02/25/22) Never had any issues with running carbon wires on point/coil style ignitions. The only place I have found that you shouldnt is on a magneto.

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I have run suppression wires on a magneto at 7000 rpm.

I agree with the general consensus here that for the ..Kettering.. style ignition with points and a coil the carbon core wires are not the ..work of the devil.. as some claim. I think that line of thinking comes from the purist standpoint. I also agree a magneto set up should run the wire core ones. Also as stated some electronic ignitions call for carbon core wires. My understanding is that just as is mentioned here about wire core wires causing radio static that same ..electrical noise.. affects some of the components in the electronic module. I would also guess, but I may be wrong the mention of having trouble starting a 6 volt set up with carbon wires was more likely due to the starting system not being up to parr with proper cable size etc.

On the right track here. The total resistance seen by the coil secondary includes internal coil winding resistance, the coil wire resistance, The carbon button in the cap to rotor connection pivot, the gap between the rotor and the individual plug wire posts inside the cap, the individual plug wires, and finally the ground across the spark gap at the plugs. Coils fire when the voltage reaches the breakdown voltage of this string of resistances. If resistor plugs are also used that is also added. Plug wires are of three basic configurations of conductor. Carbon impregnated fiber glass, or Kevlar core resistor wires (about 7 to 10 thousand ohms per foot of wire) Stranded wire core wires. Some are tinned copper, some are steel with copper coating. (near zero ohms per foot resistance.) The third is spiral wound wire conductor on kevlar fibers. This more expensive wire has a few ohms of resistance, but is engineered to suppress radio frequency emissions by being unable to create an antenna for the radiation of Electromagnetic waves.
The reputation for carbon wires being bad comes from the initial 15 years of their use, during which the technology was not mature and they failed often. Vibration and heat made them fail, becoming a continuous service issue on tuneups, and misfiring.
Today they are far more reliable and still used in many vehicles. They are now OK to use especially where the tractor is easy to start. (not an M Farmall on 6v)
Solid core wires are certainly Ok to use, but do generate radio static and EMF in the wires that can cause electronic ignition to fail, and static in home radios and (on the air) devices. I do not recommend them.
Wire wound suppressor wires are my choice, and can be used in all vehicles. A bit more cost, solid connectivity, and no radio noise.
I stand on these issues as stated. Jim

Tim, there is probably a bit of difference between a
performance Vertex mag and a tractor magneto. Now
here is where I will admit I am no expert. But due to the
added resistance in a carbon core wire the voltage rise
added to jump the spark in the plug can cause
problems in a tractor mag. So now you guys in the
know can go ahead and jump all over this.

I run wires that are a step above Carbon core most all are used wire sets I took off of customers vehicles. I am not a hard core fan of solid wire plug wires, most have cheap insulation on them that fail.

Napa Belden makes a great plug wire its all I will use.

About 25 years ago I purchased a vintage Corvette. That was my project and toy for 18 years. One of the 1st things I did was put in new Accel plug wires. They were supposed to be excellent quality. A short time later the car developed a miss that I couldnt trace. One night I opened the hood, with the car running, before turning the garage light on. Ive never seen a light show like it. Almost every wire was arcing along its path. So much for Accel quality. The wire were only a few months old. Replaced them and all was well for the next 17 years.
Moral of the story is whatever wires you choose buy quality ones. Its amazing how bad am vehicle can run on poor quality wires.

For magneto and 6v systems, I prefer solid wire.

For points and electronic, I prefer the carbon/spiral core.

The carbon fiber will likely work, but may not last as long and could be more likely to be affected by moisture and rain.

What I hear about the electronic conversions needing resistor wires only applies when combined with a high performance coil, something completely useless for a slow, low compression tractor engine.

But the conductor is only part of the equation. Insulation is just as important. Cheap wires use cheap material in the insulation, especially important on an engine that is exposed to the elements.

Installation is also important. The wires need to be separated and away from heat and metal if possible. I know, some old engines ran them through conduit, under the motor mounts, very close to the manifold. And if that's the way they did it, best keep it original, just buy the very best wires you can find.

(quoted from post at 07:33:35 02/25/22) Let's discuss plug wires. Facts and myths. Tractor with points must have copper core wires? Electronic ignition must have carbon core? Truth? Why? What happens if you use wrong wires? I got 4-5 sets of carbon core wires in a box from an estate sale...... Just wondering if they will work on a Cub?

Click to expand...

ALL cars and trucks used to have points, and carbon core spark plug wires were standard issue.

If your tractor is equipped with a magneto, then solid core spark plug wires are recommended.

If your interested, I would buy 6 wires and a coil wire from ya. I put a new set of solid core wires on my 1550 and can't get rid of radio static. I'd try a set to see if it helps. E mail is open. Chris

(quoted from post at 16:30:27 02/25/22) Tim, there is probably a bit of difference between a
performance Vertex mag and a tractor magneto. Now
here is where I will admit I am no expert. But due to the
added resistance in a carbon core wire the voltage rise
added to jump the spark in the plug can cause
problems in a tractor mag. So now you guys in the
know can go ahead and jump all over this.

Click to expand...

A magneto is a generator, so the faster it spins the more electricity it makes. Me spinning a mag at 7000 is a lot more taxing to the wires than the speeds a tractor can run. That's why I made that point. If my Accel suppression wires can live in a 7000 rpm environment, they would be just fine on a tractor.